Cpp: adding ARM support to CMakeLists. Patch contributed by philip.liard.
Cpp: adding ARM support to CMakeLists. Patch contributed by philip.liard.

fengzhyuan/libphonenumber-csharp,jarroda/libphonenumber-dotnet,weitzhandler/libphonenumber-csharp-1,weitzhandler/libphonenumber-csharp-1,caseykramer/libphonenumber-csharp,fengzhyuan/libphonenumber-csharp,jarroda/libphonenumber-dotnet,weitzhandler/libphonenumber-csharp-1,jagui/libphonenumber-csharp,fengzhyuan/libphonenumber-csharp,caseykramer/libphonenumber-csharp,weitzhandler/libphonenumber-csharp-1,jagui/libphonenumber-csharp,caseykramer/libphonenumber-csharp,jagui/libphonenumber-csharp,fengzhyuan/libphonenumber-csharp,weitzhandler/libphonenumber-csharp-1,caseykramer/libphonenumber-csharp,jarroda/libphonenumber-dotnet,caseykramer/libphonenumber-csharp,fengzhyuan/libphonenumber-csharp,caseykramer/libphonenumber-csharp,jarroda/libphonenumber-dotnet,weitzhandler/libphonenumber-csharp-1,jarroda/libphonenumber-dotnet,fengzhyuan/libphonenumber-csharp,jagui/libphonenumber-csharp,caseykramer/libphonenumber-csharp,jarroda/libphonenumber-dotnet,jarroda/libphonenumber-dotnet,weitzhandler/libphonenumber-csharp-1,jarroda/libphonenumber-dotnet,fengzhyuan/libphonenumber-csharp